SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fcffafac2964cf8393fd5c8759e001e17f7e244b6f21f2486fce79ff4efd75c6' 
  AND token = 'OKPC41epnyYwSaTnqJSua5xKWbbiPFfiYRdO240jGMM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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