SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b960139844e59daac9603236b5fdb5060a1f61ea481c60a1b1a1fb61d718dd7f' 
  AND token = 'xHwtm8nQvgf0kIpr/eywsgAonPE02LVin1Urt7SNeBs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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