SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4ed085363c31f6a851c2b263d6c784fd5da9f10e9f94130b79c7b85bbe097266' 
  AND token = 'zRpuBL8MfvMGg0e52LgQYZxbApUgSNUllUk8VBTHwqU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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