SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e1001e0558d9453fae6214d25b4cfaa2108da8566616abb76884ca87d77811de' 
  AND token = '6v/uVOvbylUyVAwWDoANrkjqtdQvs/8lUA53/amJteU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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