SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'de4999d55533b6da77eb04d316e5149dc4dca07b1874446663372645e6ded65e' 
  AND token = 'MloPZyWcCzw+6THX6DbyPoCJ/nY8MyLeQ0ca4znENbM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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