SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '631d387e85f593f0f994bd440ddc75bff681931baeb7c269ec736c701e58e2b7' 
  AND token = 'jPnEIN85THAgjFqMUkfdH0RMgR0wKKjsiMqveAjj1ME=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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