SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f0599780f412ec555919af40e73f91e524aff16360452df58043af186cd9486e' 
  AND token = 'mnIrAv28QFvwSbRsr/okFAR6PFExABxYOUoJ0jTcdes=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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