SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '941909b463c0a929e437c7d24b43410a66059a22e66be7afd1085c12f58a1431' 
  AND token = 'xp+F+KJ5DpWpTd0gJJc+d+muNvBTX6jZZhYpU0aEwUA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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