SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '14eb5b05d6ba4807fb94770ab09ee2473b907128d14685148349341003e5c4ff' 
  AND token = 'ICO4sRdMbU6LRK4FN0KbIIN1WLRsDqi7kjoCFCxwG0g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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