SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0099e3512f8f8dffaf5c97b02a2b2ca0696bc3e66837ff4b3ed8d936c3cfe435' 
  AND token = 'CpgQ81HmLlhCFsk7mlwaRqHl8mKG+VLPHnlyoZhSIuI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}