SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8441cf306358f1fea9e53cabca1d331949a9466b96c56e5f19dbc1528437d0f1' 
  AND token = 'nGCQmaPLOclVvwcay3UYpEpKDjy86ccqJVl+pMxGUmc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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