SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '67f53686beed40b8accf0daeffdbe76761ece1f8ca9f429105a9ce0277f03498' 
  AND token = 'rdwJdvbYubdttcD/4y7Kyfkg0QlRblRWZg5SxWMpT3c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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