SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5f94803f339dc217f6821a9abf373c8319aea74b9cb012f2a29fb18f6c1d72bf' 
  AND token = 'zlaFhC3Xr6Be4TyhQEHiwsWBzJoD1wUg0GEXUz9rS2M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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