SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '99ecd219c2e2a3959b05c76b7b2e6785cf66f959aeecf4efe289c4601ff8b848' 
  AND token = 'ototBc0790PZS2UIv8XOGEfA32US9TAfBJnf4jT0ozw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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