SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1ff9e705581c9c333a994970586f26cb0b75200c5a85160d04029222421fa1c9' 
  AND token = 'kTD+NzOTtigzau/oqneZgafetV3UNnXDQLiaeuWMypQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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