SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '33432daeb415d42337babf89cd4d64644e122be6eb75a31b308d8b72a7ca9b7d' 
  AND token = 'RoAdU9Ah8/ex56NyIrKPkx1sLHKMOq78/1b7we3SpvA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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