SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '25d5592e1a2baed21a735b07f6144a07df9c8266406485b9b28469fb7c5ab385' 
  AND token = 'ZkgBrV+FW9LZzJgPdecSUn59XaC4lcG9+Qkw15RN8m0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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