SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8fccf65e1b77ee258517224b8ff552300728bd8ef55b8ef87b4c3a4a4135dd96' 
  AND token = 'Rm2UHhI8w3I7qq6Lh7y/+Gup92MtUAWVCtzsnuJOwc0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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