SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8c190526f36fd98dd59b76d9aff49b3108c7fbf5cbb98f38c7af210a3822a59f' 
  AND token = 'HtaugDgPFXmGneimye4ZHTVUhum2AbW/UZEJRytSF4Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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