SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6e3c2a9f098e5543c60eeecdaf956483bf7bfe24b141d02580ef8ccf0055ad6e' 
  AND token = 'scbdc6yEajG4xWR4DEkZsyMx3xMOoKTK+GeicXna5FI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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