SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a9a033226ef5d69428f14ecaedd17cc4bbcc9576e5b7e02646357d8e67575e0f' 
  AND token = '4nHRDCZEa8jFTruWjjTBS2m/rfoYYQQaH6RfRlV/6uI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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