SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7dda87a26bcb974dfb63c6a83487fa001688ecd4588c7439aa84141c215109c0' 
  AND token = 'OZacHPQ5fcIQANjuGDN8T9V41RmZ5ExlWhmZ3sCmdSI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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