SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '88b1f752f1e214fa787118ed3e0b3df8a500ff4a353574c782cb6158f691064f' 
  AND token = 'P3loT4XFjVIgWdYJPJ/yxE0ThiQ/ZUByB9hGtUHkzB8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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