SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '52eb8c6f36f1eb150a5921a3b9078880b1ff3cf221a612c43ee0d736f4bf5ba7' 
  AND token = 'FghYO/InQ0CY/FPpR2TEd+gWhnoXli/DvTK+7PF007w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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