SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '70e75d38e07e266493856812b738d52ae836a498a4d8aa431a0d262cef1bdcb4' 
  AND token = 'L9P0oYDfO9PAGpTLvV6/ANdQLWqLdbTkIqzrAuwuqZ4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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