SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '78c2fa585d28bfac4be093ad4cfc3497cdf3a9a71051d52a48e7a872c2fa15ac' 
  AND token = '69FszYqp+zGFHwXbGPsxX0JI/FqjIyHXQZeIkrNCNCo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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