SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ee2ac6911d8eb8dba21bef796d659af83181d2c7383d761024564b2acfee4a74' 
  AND token = 'rJEIqzwsAmZNPYgfCCci5Qmf+WUf9ROzSUgkNz4LX+g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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