SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c2ab6e80c47b4badf5021ff6fc1736ea1a3ea325b466d76ebfa5ccb06b9308bf' 
  AND token = 'Hv6oWOEzXucNmKCuC4TAHr7t+5rV/dHbBmNZSaykdd0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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