SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fbbc62b272f81a96389d6756d0b8ed1ebd236b96123d57c91229150fd008faaf' 
  AND token = 'yXgcdmnrClnnbl9beLKRET6UMqUpcEj3S86bTUPtyHw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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