SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '84c3406130597f3f6ed866f5ea1c61aa9e3dd7b50b134a8f7c9b43f38d81c028' 
  AND token = 's/gTLOjqtkkSHODqYoqJReRU7ksqdznihKfOSw/qMQo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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