SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '55f43ac637110f4fe04c2d57541ed324fe0043354911e2d6a3a58707febd5f76' 
  AND token = 'zhEoTk1HGrgGFr6XnOYwK0W9WxP8luuvzvJQQju9ypY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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