SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe1cb1ed425a7c9c1a20dc48ccdf27c98269b3ce0afd6e92cc3d2325f607498a' 
  AND token = 'eJmy19/pFJ5+B3BjTS10aaK5QDH1twoCXgyOKc6je0A=' 
  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"
    }
  }
}