SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'da2d2ece74b13502cf063735c392374631d328ae92022d41b3dd6e603520c50a' 
  AND token = 'gJcz3UThX7P3R9X1dpQuncBLh15xxy+t1FptdFUVF0Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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