SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a65fa7c40ac1d31fb202616c6fec6841d8c5ca14dc58b5200ad753f11af85dc' 
  AND token = 'CLrWjbI/bFiZjRVplgs1QnmUOdYzV+rbl9ZslX/Jh9s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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