SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '983d284a4d74f366af3fa3d2af0a370fe6ad4d85ecf543ae912bb2034cdc3331' 
  AND token = 'tDJhw6CD5YqGJRXgStO9PYdb0uj/zi/Rn0qmKuvyJ+Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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