SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '49bf04248565a41592627d9cfbb21515259ec72c47ddfe097c7a3f0ef1137d45' 
  AND token = 'C5NYP3b7Espn2bRWMmz8CcoijPBfjbc39I56seLtvjM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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