SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cddda449c5a6f9cef43c3083900a87037c012bcbae22839ae62a5040f2e63137' 
  AND token = 'oIL45oxlhQHGiTs7cUfOvkferc+KJxXvx7Gpn/oHAuw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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