SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd61b52064c9b13c0780cc9653bc44ce276e53ae3c61f1f4f347c4019f23f16dc' 
  AND token = 'O1MUJ2ntkfE0OiFro4/Yk5kL8DahyHB/yYhv2sE72Fw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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