SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '452030d774c9b4881b53f8d7681fc119d8973d806da4fccc0290f37f87d6ec80' 
  AND token = 'VyKfzJ/iMqjQoaG4JMse05L4tcepH0He/mesRJgTGjw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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