SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '532abd3a6fc68706b06c45f471292e15fbd15fce2f7741329458e9acfd0d6a6d' 
  AND token = 'r7WV0er8oqVrGHZm9J9AcCWmjWSBA2Gve+IcFCAGvgQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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