SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e8297ab56e5b5acd6bda253e501ddfbf4b946acca6a073c05ebceb24a53ed7be' 
  AND token = '439hqsJLj1esEqwmLAAwOZKwBlIUlNIPhOmZ0dwlfOQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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