SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '824c9f90dc4b22208b23ef7bbc6554765c5583bdf94918edf03e2382dc853d54' 
  AND token = 'L2jpL0lc90KsFgJIlOkUnlNeWhc4Xy4DDsPCvx55QVE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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