SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe892410814c072ac51bb66db84c0b940d785a423bd01e64b6bc67e9a767ed56' 
  AND token = 'FpYBQ1YAs9YWOBHaNnsKHrnWkwqpOL7tMLESVbbG4/k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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