SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5d4782643332b59fdcf0cf9545d328c01d6796415aa734f7287a84f8c7f94a44' 
  AND token = 'Huefl+29lgUxAI0laWSwCp95UQWEKcd1TCiYUIfI6QM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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