SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fa754d45b1aa05ec4c490dfb8c78818203ae5f711042a39f2a332b131de870db' 
  AND token = 'LQIjJxC6fEdWZco9wkO6yYu5YRhwcvnTsuxDIbL7YtQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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