SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5fab026e9e2982365f652284ceea0c096f56af063c6ab46f56af9b4e6f9d1115' 
  AND token = 'ylahUJClNiaWa8ydatpbkNnsXVt0mfuY5jOJEgWSwP8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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