SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1adf77b8f6ef339756c346b3451aec2e63316b389f013cf67ae183506a1201e1' 
  AND token = 'p3/ulYwkUHX/WZC+6tGMw0qhwd9ARSKH1uuGcUnGgf4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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