SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c96b2af39c2088e808f4f81345ae5bf2db9aff3b0fb2fcda2f1b38bf930c33ee' 
  AND token = 'cQGrsq9ZuUxWeW1Ax+IFO6ko3fQyTcEXi92h/qFq5gs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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