SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4a13c290d5d4f0103fc0185a1270fd1d93ceb63e7f84c27b55b5615856158778' 
  AND token = 'NAidAqrD0i2iUnRbZCHhtbWgmuIVVVjsdWoOG20ZoHk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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