SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ce11acb2a5f971dce1ba50dd4592756ba051a53be536bd3e39fa646e1d567e8' 
  AND token = 'sNmHdJJiIe9YJIUxTdLMvHBRAocHzprJWMf5I6GFlB4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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