SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5bf153b30653d710c7a61c42df2912899c963d9d2b6e19fe7519059e24b74522' 
  AND token = 'c0PaNTnvXyUcEjDh3p9F/HfiToj75zY3PaOV101WTK8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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