SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66abd4d19a6edaa5730d236a5458f4cc8aeaed46650edfbcd95170d8f441df49' 
  AND token = 'oqMhtU2wMLtWmTkdJYVp9AlZsHUr8lBvB5JN5Yl0af8=' 
  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"
    }
  }
}