SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0e91dc8fd246425c6504e02e9aff439d0a3b4a71bb2bdfc227cf0de9f1637769' 
  AND token = 'Nj33r7qLitdOXwloKx7RKctBFr6w3ut4+2SkShQamn8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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