SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '65019d436053fae8602088614b97b876e1828449f4b3e49d2aa230885db204b8' 
  AND token = '0GvlxV7YcgJGwe0yTdHoq6332q4XyqsaLamnSdMZizk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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