SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6428b70d52fdf2d7320563b936b83e52b23bb4615000973e98340549334bcda8' 
  AND token = '+BCNo6TMKE4ANsoIdjDIxinsSMlminHi/GedJHKCuHY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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