SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a9bce869b905b028058423aae722b498f030f1a94700f520326806f7026e4320' 
  AND token = 'ufXO2hsO7YVeYnC2FlcxH4Ymo0hpTfjKRGBphPV7psg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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