SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '95712fce14236bcfee7b54ccf9059abe24b5c0dd880b16fff96df1bfe7047a65' 
  AND token = '/vNUBpgKoSwA7GjZZ68FTNlrTInxLmOiv3lEgqmHPD0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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