SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '96cfaa51088fa8b1b539888415082d6270d16ea614fca5ae1201319962fd49b2' 
  AND token = '3paqoFGOUDvJSbeRDsgujI704Q0DJN7FTZaE1SauT68=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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