SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1cc836e26d08b16bcd633d0f9908590ebefd91ff2f758b47061ab9a450c408bf' 
  AND token = 'xjLaJhw8J8uWCMi7Z7gctCM67eoeMqBTl4x1KxrzvTA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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