SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '84f45b139ac7d065913de630f3af8c5b09b502159294cb7c0633c887aea2c276' 
  AND token = 'Jt1l1xxXOKYhH/BJDGBLp2/i7zjruZumOrfcvMvHHTg=' 
  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"
    }
  }
}