SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b83c47870cb39d0b78fb41261e85e760bf3105fc77e327846d3499d7063b92fd' 
  AND token = 'bCohDGo/uqn5YnmlgkandHbaBZZEDNI4X0lYC+P7IvI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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