SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ffe859a559ef3dd17c3e0c8de2bf1c1ba7001084a580a2984d6c9379b38cfd49' 
  AND token = 'MOgvcmAXtLLvgyYIE4NFOIyFMJG8Ooewulp0wxWnL5k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}