SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4ea232f4086803abf7dd2134cc2958592ad38988a9592e368f67dc5a6766cb28' 
  AND token = 'tFNSsvvi+VCP2mloQpr7WHwdElgL+TkOgYo0hzYtjiM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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