SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '73c2d669a5e9dce89ddd3347a76ced8752012d9a5d4443c9977cec8872759228' 
  AND token = 'NBUZNS15sKqR6qmVlFPB82G/o45LubWX2WrhWrgbWOs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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