SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3cc606b9c182d1ce26aad993457e5aeef3fa139d89dca508524d193e52d5be82' 
  AND token = 'GjVLTNu2SQKFUZsyJnGZn/hdAT94H3CJ+erCoYzNL4o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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