SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8d3e009c7aa775a921e9265b0ae17ae880584b590209c65421b0b6febd4a3436' 
  AND token = 'fcf7ROULbDRZfj+lVV/4ux+HLRadcJsrSvzETAB0o0U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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