SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '04cb3a6a43dc78127e28b12cbd42d84983cde6dff0c8fddb6542da89f668d16b' 
  AND token = 'lwxKQLftZhphiAL2YXv5jmHfX2lPBMRAhQCdNmYaqWI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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