SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2343ab6b973cf7309df555b510d5249f9bfbbc6c42b45f63dffa4e966cbf83f6' 
  AND token = 'FfC4fn+BgOx59iX/eMC9MSEPlxVxgnF8o6Og3P6jRHs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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