SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ac9f06b6ce1a6c7376fc9bf119cc84f9466c6cf36d4cb2b2352c4da29ef9133' 
  AND token = 'ErDF535TC/wOc/DY4atIfCFXXrlw+YL3EGzI0nOVpzA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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