SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '733671e882d9f61f2c2fe7d126f562cbd12f87027afbac47cc3ceb522cb28355' 
  AND token = 'N7MGtcLD+ur5TVKonmgwTaCckemObAVkIUHK7tXu1Og=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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