SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f0409bfe4dd5808fc9a21a732d1a9197c1a6ba756362d28858b64f557c193efe' 
  AND token = '4wVjaYJkHTPHTwTNxp1mA3Epdwwo5EK1Xn9U2Um3TQo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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