SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7c5719c52ea32d593b3868599be4b469bd6ca727da4d76bdfcd1e2485d293a52' 
  AND token = 'Ggvq9ESag4sWbMUpZ3oeYx6wI2goNa7GXVv8Q0yw40k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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