SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2402e05da42a903897cd5e6ae204d75f332c9460d18fedec486d1a32b2720a7f' 
  AND token = 'Egw5b3HY5GuB6jtvR7XO7HsHNgYLChUkyDVjLq9lwKo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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