SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cb7be0b2b6e27afa44135328cd18b834a8e7a79ee2f1ab166057425e7609d818' 
  AND token = 'jwTJsQqxtmDye8APqzAqam5J+fb7V/nTQdBvOpNov/w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}