SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a41d2b21cbea43b37bf7f9b8012ddf2e78e50750cd363ba74c901362bb88ac5f' 
  AND token = 'lHAsHvGt61+I/QCIWw0CsHFZ55XCoZv95szGsPVaEdY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}