SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e3770abbf064f1f745f4abb86b6cd305de184f72219a7ed8fa14a2a06826a0fe' 
  AND token = 'hupLSpjucrGI+5+y7GOXOvOBrlr1LcRxq84mLFmlIwA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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