SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd188583766c17dfbb1fa1147dd0fae8d1bbfe14e694b7c44ca3ad3fc168dbc1a' 
  AND token = 'VtbJ4qkptK5InDlXNyqt1+53nwjj2ItEFvnfxru5E+A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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