SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f1d3ad3fd7aff68465d0313f85f730f69a7e893c9105e0d90c5d43b7149a3f83' 
  AND token = 'pNPeBX7JAJ1slTf4YaMhYemaKVRxBEUqmmE9vGtdcNY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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