SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9bf1c610646a8982bd0e0ae6f73f284180b7b08870c818d5eaa305317eb73c83' 
  AND token = 'IJdpY6zFL3kMwmtaFgmm6XIcSCngxz9rElztEFN29EY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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