SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4bc664d8ad6b3be26fbc4f314ae269e512e2495d651056828a6090a954abb358' 
  AND token = 'jnP/6ySpHPE/+JdRWnMiXpJNKQsaJqJWcyrgB/ahF8s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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