SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e50412860289190e0b9432a954c92277b95845e9515e320aeaa594d3bc3c8108' 
  AND token = 'v7TniBLcBXE714FAhrCLFSW52UL/HqBIRUQGRiE4wqA=' 
  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"
    }
  }
}