SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '963b78815102781781f90be72d4c685a1d154b07337adebe3599a115d76c9507' 
  AND token = 'uPPUQQFoFkwcYYuUTegvAXHUc5tKYiQ5bNd1tbCXbus=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00109

JSON explain

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