SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '36e0b4f577b1ccf6b8f42e52425651959d46f7a2328c63fc9c6e722432c3dd9f' 
  AND token = 'DYYhAYnkWgEgQiFbx5BX3/Bm1tS/m9pSkdXreUst264=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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