SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aeef09da717c61971984b9d4dd583e1de6b6f3b0c6cb686f969fcad383d3e33f' 
  AND token = 'SGdXeiTuuwegDONnfCJCLSFwsETNwUSZAYwqS68PcEg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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