SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bb2be00272e658fe3b6b1d09167484aa645bdcbf26791f7ca18052b31fa4b274' 
  AND token = 'yeBMeKVIsTlPLQzKXgLRq4CZuxmPYBi12Y30XYWeQg8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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