SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '417290f08beecd2871c221db00d0dc8236b669fdf04d1b54527b53460623de38' 
  AND token = 'uXX/bo9aQLw3kINugamA/VeWA2m9F9yHqqYTBCdiA1Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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