SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f817607aabd964588271ad1524010ebe5863be223002fd6a6376fa23e0d04d0d' 
  AND token = '82tFTfW7oIuVNZ3RqFFWinjJHh0MLnsT5GccwH72Kr0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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