SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e94ab0e211e0b411ae412c3009763735f9cf07b2f070972c257872e9e0a848a6' 
  AND token = 'NLQRwPC6iNwC8gEAMFvBEgGSZ24NUIZSd/e5Ylph1P4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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