SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e0b6bee84f1d5c3705e72851ca22910656a8757a4d58edf72423f666c3cff08a' 
  AND token = 'fzk6Vv/VzHTIcubo8VkG1CswKmuT3y94+5jsgwqJMqA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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