SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f96f36ee3ddc2abf5fabac75a6488795d5351c9b41201188a183746858c0c7cd' 
  AND token = 'pL2Zlhh+yCVt5SIwJBdI00x1yIMg7+uztGXC3oqXK2Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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