SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'ba7f8cbe4328e256423b15ceec073940c9bcd75dceb151038222a04cdf358e40' 
  AND token = 'WX4MP0F2xXw8HEGzK6mQ14CPA5uTfJqCeyiqrw3G2+g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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