SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4bbebda9afcd424dcbb086ed8ebade8284f5147f4b89b44473d3f73ceb267073' 
  AND token = 'IiZvqYSsnPp7I3e8nKn+jyLfiq09vNoivmkt4TzAzko=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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