SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0291915eba50ccccc2c9ae5b8ab34e72cd366822d23dc4c3b11f61f03bfaa1e1' 
  AND token = 'BGT0pWYzfcQ8CCQRoP3QAgWHiXlUii2hLoP28ETXm+o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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