SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '96cf2264bea6b07f0294d6947b374dfdec5454e8f96a3ed56c9f02886239db4c' 
  AND token = 'hbrhXdmVnSfkrIanlFvLe4pRCjs79Gyl8B5wKChUi34=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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