SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '95528e6514ece0fba02e84ec19c7f7a318f06374addbe12a397c8347046d81f3' 
  AND token = 'hj7EfMWm1Ee7LYuq4//NCFxTeOpWBbj2RkdosU9I1PQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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