SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '04f2eec1a41b3ef53685b6bc97c6e42593c7a82aefd3c4b4b5f40d494ff9e0ad' 
  AND token = '1PlxS2TVgmFfquQH/lzQGIKgy7zpXmp1P0tvQu7iCZ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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