SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f661ab57ccce561ab22d81818b8da4ac8229628c55664f7abb9bf6569462ce72' 
  AND token = 'IsFb72LBZBg+VEQNvnLzm0oPu3Xdu7XVKQiAMczZVuI=' 
  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"
    }
  }
}