SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f628e0f41bf88ee2e9387ca7ac8f0457b8325e1343e15bab6730c72abccf580b' 
  AND token = 'ukZMkIMsm3EOLjWRvTVFIAkJFpK+rtzMUUJMKeWXPLw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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