SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fdc8c3679ecbcbe99f80942ffea3633d84d32ae7033ac8cab6da552953835bc4' 
  AND token = 'nxHZmaBG/ANLHDOu5Wiy9XJTmUWhuqM894qjSGdtii4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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