SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f029c6791c971011e5a1c7888217b3dbbedd15570b67feb42d0db6ab53da99a5' 
  AND token = 'NbI7ALNIfsjidtRVbRFqvBaCz6luba7/vZVNjKhEXi4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}