SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f12970cbd7269899ab022a5ad7fa6d281d0a6b63ce2763c62a1dabecfa49e16f' 
  AND token = 'MWFIh1687FHgn2iPcekL/9d63ot2xo/eprD/uCFkMOI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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