SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f112e3acb2d08538e8da4fc4821be20680a01b54fe3704b0482f9cf8a50e1c61' 
  AND token = 'bQUUvlSKwYQtw9sqfGl3gdN/4tJUOUpVm+rMmJ+CwLM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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