SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a24c5cddf6d5caa74d500caf6c4cb077f18a9082f90afecfe39b9241a7b77150' 
  AND token = 'bvvEv2rcEyKCu4AH2KjheVYNsVDOML57UnSeqUjoswA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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