SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b485f2d885e01c6b413bacdf6992e23f5e0820778c90fca24d074cc8f4728ec1' 
  AND token = 'FwVyxHiz78e+3WNWhrf2WDnejhnpRIO9ISkHivRJ6Yk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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