SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c595ef2e0b5dc5bab6b70aa993b86bc6dafdfbb17d676a1829aa350240a851a5' 
  AND token = 'SJDFH6neNv27ytkibvB9N7YA1VpiYu1rR+JOPHx/uyc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}