SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6d73ff8d137fb3bd0517f3516fbbd59cab8c69dacd005b35675fc6452e596235' 
  AND token = 'OoqRFUqyxhOhbDhJOUlFmRc9F7ZxSJIs1O85JyURtqk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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