SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0e0879fe34a3451ee254ce58f6129e0caaf9c3a6a775e32f7d5b4c1f95979a7e' 
  AND token = 'rwE6rYwfL/UNvnWJcwcI8GpuAZfphnwXhP7rO3wg/iY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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