SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7c93358ebf2041b002b4504a396dad206a89d70c70fb9b6b5c55aa30e23adc06' 
  AND token = 'W3rLNnrpa8Ef2dMUDj3nUIZCmu+wFpgYwxFSFGb9U4A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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