SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e06bac32049cf3dbebfc81bf83031b9afaaee9f893e7173cc54ebeeb62086212' 
  AND token = 'qNalAkS3cDyjGx0NUOiFLE+ISNSeaF2MkPyTeQO/FGo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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