SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e4667fd8d7541821240e2f4fe02fe177c619978caeb7789bc655dcfd126671d' 
  AND token = 'ZUzVpuVnORWc4KpFSJRwQS8d9BklDDh6p8n1obbU5Pc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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